hammer and tongs

東野圭吾の小説 "New Comer" を読んでいます。

'Only old-timers would say something like that.'
'Those "old-timers" are important customers for us.'
The two of them went at it hammer and tongs. Naoya was struck in the middle, unable to take sides.

"hammer and tongs" も大分前(7/28/2013)に取り上げた慣用句でした。前回はMerriam-Websterの辞書だけの引用だったので、今回は別の辞書の説明も見ました。

・Collins Dictionary: If you say that someone was going at something hammer and tongs, you mean that they were doing it with great energy.: He loved gardening. He went at it hammer and tongs as soon as he got back from work.
・Dictionary: In a manner indicating seriousness of intent and capability of harm.: When they had an argument they went at it hammer and tongs.